Inkjet and laser printers have become popular for printing on media. For instance, such printers have become popular for printing black-and-white and color image files generated using digital cameras, for printing copies of business presentations, and so on. Most computer users today employ some type of printer in order to generate hard copies of digital information. A printer is more generically an image-forming device that forms images onto media, such as paper.
Fans may be used in printers for a variety of different reasons. A fan may be used to create a vacuum, to hold down media at a specific location for optimal print quality. A fan may also be used to convectively cool the components of a printer. Alternatively, a fan can be used in conjunction with a heater of an inkjet printer to heat media, so that ink applied to the media dries more quickly. The fan may also be used to exhaust fumes and ink aerosol away from the media.
For achieving desired performance levels of such fans, knowledge of the local air density is useful. For vacuums, knowing the air density within a printer assists in maintaining a relative pressure between the two sides of the media. For heating and cooling, knowing the air density helps to maintain a consistent air mass flow. Other printing parameters that benefit from knowing the air density include ink drying time, the temperature of the heated air moved by the fan, and the media advancement speed through the printer.